For the past few years, David Cameron’s Easter messages have had all the sincerity of a hostage tape. “Easter is a very important moment in the Christian calendar,” he would inform us. Or he’d quote St Luke saying, “Do to others as you would have them do to you”, as if this were a Christian insight, rather than a basic idea embedded in every religion since the time of Confucius. Such messages were well-meaning but sounded as if, having sent greetings for Eid and Diwali, Mr Cameron had decided he’d best include Easter, too.

But this year is different. The Prime Minister has launched what sounds very like a religious manifesto, asking us to be “more confident about our status as a Christian country” and more “evangelical” about the faith. This fits a pattern. His Government has done much in the last few years to expand faith schools and help repair churches. The Prime Minister has appointed a minister of faith, Sayeeda Warsi, who declares the Coalition to be “the most pro-faith government in the world”. Something is definitively up.

When Mr Cameron came to power, there was no talk of religion. On the contrary, the Tory hierarchy seemed – if anything – suspicious of it. There was a manifesto pledge for a marriage tax break, but George Osborne insisted it would be delayed until the last few weeks of a five-year term. Tension began to emerge between social liberals, like the Chancellor, and social conservatives. Iain Duncan Smith, a practising Catholic, found himself under suspicion of having a welfare reform policy driven by a religious idea of redemption.

Just a year ago, a senior minister told me how those with faith had to cover it up. “For most Cabinet members,” I was told, “if you even mention religion or God, they look at you as if you believe in fairies.” In some cases, you risked being laughed at behind your back. The Department for Work and Pensions would be sneeringly referred to as the “Department for Worship and Prayer” (Steve Webb, the pensions minister, is vice-president of the Liberal Democrat Christian Forum).

It is a Muslim, Ms Warsi, who has done most to confront this attitude – and to start the change now under way. When she became minister of faith, she agreed an agenda with Mr Cameron. The way the Government talks about religion had to change, she said: people of faith should not be spoken of as if they were oddities, minorities and foreigners. So they should aim for a “normalisation” of faith – Church of England charities should be able to win government contracts, just like other charities. She found in the Prime Minister a ready ally.

The threat posed to Christians in the Middle East has also become clearer over the past three years. At first Mr Cameron’s Government had been very hesitant to say much about this, or to accept refugees in the way that Germany had. This is changing. The acceleration of persecution, including in Syria, where another priest was killed last week, has reinforced the idea that Christianity does need vocal defenders in the West. And defenders who will insist on religious freedom when deciding who should receive aid handouts.

The Prime Minister has also come to realise that the gay marriage debate – and the way it was conducted – has upset more people than he expected. Ten years ago, Tony Blair passed his pioneering Civil Partnership Act with minimal fuss. There was no such reserve this time, as the debate was conducted like an American-style culture war. Many of those opposed to gay marriage for religious reasons have been left feeling as if they were being accused of being bigots. Several Tory MPs say their activist base has never quite recovered. So there is much repair work to do.

Mr Cameron also needs to start winning his battles against the Left-leaning clergymen who oppose his welfare reforms. He is portrayed as having no moral agenda – and, ergo, being indifferent to the plight of the thousands queuing up in food banks. Earlier this week, 45 Church of England bishops signed an open letter saying that the rise of food banks exposed a “national crisis” and the need for urgent action. The Prime Minister has found himself the target of very well-organised Anglican opposition, and needs a better counter-argument.

It’s very easy to find one. It is precisely concern for the poorest that has driven welfare reform, and why Mr Duncan Smith decided to include food banks in the welfare system. This helped them grow, albeit to a fraction of the size of their equivalents in Germany. Successive studies have shown that the proportion of Brits who struggle to afford food is falling – and lower now than five years ago. If anything, the scandal is that there were not more food banks in 2007, when there was more hardship.

If Mr Cameron wanted, he could pen a pious reply to the bishops. Where were their open letters at the peak of the boom, when a quarter of Glaswegians and Liverpudlians were on out-of-work benefits? Where is their open letter in support of his plans to recognise marriage in the tax system, or the recent progress in family breakdown? Do they have any evidence to link the growth of food banks with a growth in hunger? It was striking that the Archbishop of Canterbury did not sign the latest letter, perhaps recognising this as politically driven spin.

Mr Cameron’s Government does not lack a moral agenda, but does struggle to articulate one. In a way, it’s a refreshing problem: for years, Gordon Brown spoke about the “arc of the moral universe” while saddling the next generation with billions of pounds in debt and creating huge welfare problems. We now have a Coalition Government that has an impressive and lengthening list of social justice achievements, but doesn’t like moralising so can’t find the right words to boast about them. This is why it now spends each Easter getting beaten up by bishops.

It could be that Mr Cameron is growing more religious in office. Those who worked closely with him before are taken aback by his latest speech, saying he showed no signs of such an opinion a few years ago. “Religion was in his bone marrow, but never his muscle,” said one. But Downing Street can have an evangelising effect on its residents. When James Callaghan became chancellor in 1964 he was a lapsed Baptist, but started to pray again when the horrors of his job became clear. Tony Blair’s faith hardened in office to the extent that he set up his Faith Foundation upon leaving it.

Mr Cameron jokes that Baroness Warsi has made him a better Christian – and that her openly talking about the need to confront “secular fundamentalism” is rebuilding an important part of the Conservative message. She now talks about the Tory party’s “faith in faith” and “devotion to devotion” and wants to use this to distinguish the party from Labour at the next election.

There is obvious potential for disaster here. In Britain, there is a long tradition of politicians reaching for the divine and grabbing something else instead. Even Margaret Thatcher came to regret misquoting St Francis of Assisi outside No 10 (“Where there is discord, let me bring harmony”). Discord, she wrote later, was inevitable. “I never thought that Christianity equipped me with a political philosophy,” she said – just “standards to which political actions must, in the end, be referred”. This is what David Cameron is ready to say now: that once again it is time for the Tories to do God.